For many years, Microsoft's Internet Explorer was the undisputed king of the Web browsers. Nevertheless, its limitations and safety concerns have caused it to give up a good part of its market share to Mozilla Firefox. While IE is limited to Windows OS, Firefox is multi-platform, so it does not matter if you have a Mac or Linux OS, there is a version for each of them. Also, many studies have demonstrated that Firefox is safer than IE, which is an advantage if you make many transactions through the Internet. From the user's point of view, FF uses far less memory than IE, which is a great advantage for those people having older computers or OS (IE's updates are limited to those systems having WinXP Service Pack 3 or later). Also, this allows you to navigate through various sites at once using several tabs, without compromising the speed of the web browsing. You can customize your FF web browser as well, by adding any of the huge number of add-ons available on the Internet, like graphic themes, calculators, Web-mail notifiers, translators and so on. Also, if you are a Web developer, you can access to FF's code and create new applications and add-ons, since FF is open-source. In short, Frefox is an excellent alternative for all other web browsers.